Ring means for fastening insulating spacers in concentric lines



June. 26, 194-5. L YOUNG 2,379,331

RING MEANS FOR FASTENING INSULATING SPACER-S IN ,CONGENTRIC LINES Filed May 1941 INVENTOR Zloydl 0W 'ATfoRNEY Patented June 26, 1945 RING MEANS FOR FASTENING INSULATING SPACERS IN CONCENTRIG LINES Lloyd L. Young, Patchogue,

N. Y., assignor to Radio Corporation of America, a corporation of Delaware Application May 9, 1941, Serial No. 392,726

1 Claim.

This invention relates to a new and improved means for fastening insulating spacers in concentric transmission lines.

An object of this invention is to provide a means for slightly deforming a tube at a plurality of radial points on the outside of the tube or shielding conductor and also to remove the previously made deformity on the tube.

Another object of this invention is to grip the insulators and to deform the shielding conductor by means of a ring threaded to receive three machine screws, and an ordinary screw driver.

In the prior art, various methods and means for holding insulating disc which are used as spacers between the inner and outer conductors of a concentric line has been suggested. There' has always been a long felt need of retaining the insulating disc within the outer conductor by means of a simple method which will require a minimum amount of work and without the use of special and elaborate tools or equipment. Also, several prior art methods frequently gave rise to a corona discharge from the inner conductor, due to the retaining means presenting a rough surface. A device employing a split band clamp for deforming the tube and retaining the insulators in predetermined position is disclosed in Hansell application Ser. No. 393,682, filed May 15, 1941, which has matured to Patent No. 2,333,- 005, dated October 26, 1943. It is one of the objects of this invention to provide a method of holding the insulating disc in predetermined po,- sitions without marrlng the outside surface of the inner conductor, thus preventing corona discharge, also, this invention provides an outside surface of the inner conductor which is free from metallic clamping members, which has previously been used in some of the prior art construction. This will best be understood by referring to the accompanying drawing, in which:

Fig. 1 is an end view of a heavy walled ring member of this invention;

Fig. 2 is a section of Fig. 1, the section being taken on lines A A thereof;

Fig. 3 is a section of the outer conductor which has been deformed;

Fig. 4 is a longitudinal section showing a plurality of insulating spacers disposed within an outer conductor of a concentric line; and

Fig. 5 is a section showing the ring of this invention applied to the outer conductor of a concentric line.

Referring now in detail to the drawing, a ring I of rectangular cross-section which has a relatively heavy wall thickness with respect to the removed. Disc 5 is made than the inside diameter of tube 4.

wall of the outer conductor of the concentric line and has three tapped holes 2 for receiving three heavy set screws 3. The holes 2 are equally spaced in the center of the ring so that they may be made to bear against the outer surface of the outer conductor 4 of the concentric line and thus deform the outer surface at a position which is central with the center of the disc-like insulators 5 which are equally spaced at pre-determined points along the inner conductor 6. The wall thickness of the outer conductor 4 is relatively thin with respect to the wall thickness of ring I.

In the operation of this device, the ring I is positioned at the place opposite the proposed location of the insulating disc but with the disc 5 only slightly smaller The disc 5 is the ordinary form of insulating spacer having an aperture of the proper size for the inner conductor 6. It is composed of material having low dielectric loss at the ultra high frequencies. The inner diameter is made slightly larger than the outside of the inner conductor. The outside diameter is made but slightly smaller than the inside diameter of the outer conductor 4, and for ease in assembly, the edges are rounded over slightly. The outer conductor with disc 5 removed may then be deformed beyond its elastic limit, as shown in exaggeration in Fig. 3, so that it is permanently deformed by means ,of the set screws 3. If, now, the set screws are withdrawn sufficiently to turn the ring approximately and again the set screws be turned down, it will be found that the pressure applied by the ring and set screws will largely remove the previously made deformity, as shown in Fig. 5. If now, while the ring is in place, and the previous deformity is removed, the insulating disc be set in place, and the set screws loosened, the deformity will again appear and the disc will be tightly seized and held by the three deformed places as shown in Fig. 4. The to the next place where it is desired to position another insulating disc. After all the insulating discs are secured in their proper places, the ring is removed from the outer conductor.

A modification of this invention might us the same method of deformation as mentioned above, except that it is applied to the inner conductor so that the insulating discs are held firmly within the outer conductor and may be madeto hold the inner conductor against any possibility of lateral motion within the line.

This invention should not precise arrangement shown.

be limited to the ring I may now be moved What is claimed is:

In combination with a transmission lin including a metallic tube, a plurality of spaced insulators located within said tube, each insulator having a central aperture, an inner conductor 5 passing through the central aperture in said insulators, means for retaining each of said insulators in spaced relationship, said means including a metallic ring member having a wall thick- LLOYD L. YOUNG. 

